The wet performance of a tire is one of the most important characteristics. Demands for improving the wet performance remain high. As such a technique, silica-containing compounds have been used, but further higher content and higher dispersion of silica and resultant higher physical properties are being sought. In the past, as the means for raising the dispersion of silica, the art of using a terminally modified polymer is known in the following Patent Documents 1 to 5 etc., but techniques for further raising the physical properties are being sought for high silica-content rubber compositions for pneumatic tires.
Patent Document 1: Japanese Patent No. 3488926
Patent Document 2: Japanese Patent Publication (A) No. 2000-273240
Patent Document 3: Japanese Patent Publication (A) No. 2004-175993
Patent Document 4: Japanese Patent Publication (A) No. 2005-248021
Patent Document 5: Japanese Patent Publication (A) No. 2001-106830